摘要：

采用国产大型湿式氧化装置处理乙烯裂解废碱液，其出水COD小于1 000 mg/L，硫化物稳定小于1 mg/L，平均COD去除率为96.4%，平均硫化物去除率大于99.99%。采用以耐盐菌为核心的好氧生化技术处理乙烯裂解废碱液湿式氧化出水，直接生化处理的COD去除率最高为40%，而苯酚协同生化处理的COD去除率可提升至70%。当用苯酚溶液将乙烯裂解废碱液湿式氧化出水稀释8倍时，协同生化反应36 h后，COD可降低至50 mg/L以下。GC-MS分析表明，湿式氧化技术高效去除了乙烯裂解废碱液中以硫醇、硫醚为代表的恶臭物质，而剩余有机物通过以耐盐菌为核心的协同生化得到进一步去除，最终出水中仅剩甲苯等少量有机物。

关键词: 乙烯裂解, 废碱液, 湿式氧化, 耐盐菌

Abstract:

The domestic large-scale wet oxidation device was adopted to treat spent caustic from ethylene cracking. The effluent COD was less than 1 000 mg/L, the sulfide was stably less than 1 mg/L, the average COD removal rate was 96.4%, and the average sulfide removal rate was greater than 99.99%. When using aerobic biochemical technology with salt-tolerant bacteria as the core to treat wet oxidation effluent, the COD removal rate of direct biochemical treatment could reach up to 40%, while the COD removal rate of phenol synergistic biochemical treatment could be increased to 70%. When the dilution ratio was 8 with phenol solution, COD after 36 hours biochemical reaction had decreased to below 50 mg/L. GC-MS analysis showed that wet oxidation technology could efficiently remove odorous substances represented by thiols and sulfides from spent caustic, while the remaining organic compounds could be further removed through synergistic biochemical treatment with salt tolerant bacteria as the core. Eventually, only a small amount of organic matter, represented by toluene, remained in the effluent.

Key words: ethylene cracking, spent caustic, wet oxidation, salt-tolerant bacteria

中图分类号: 

• X703